CN1708139A - Virtual exchanger system - Google Patents

Abstract

The invention relates to the technology of the public telephone exchange network, and discloses a virtual switch system, which enables the existing CENTREX service based on the PSTN network to access IP group users, and realizes separate groups of IP group users and IP group users and traditional PSTN users Mixed groups provide WAC interface and services for IP group users at the same time. This virtual switch system completes protocol conversion and media conversion by modifying communication nodes to add packet user interfaces or adding gateways, and realizes IP packet user access in PSTN-based CENTREX.

Description

virtual switch system

technical field

The invention relates to the technology of the public telephone switching network, in particular to the virtual exchange (CENTREX) technology of the PSTN.

Background technique

In factories, mines, colleges, hospitals, government agencies, group companies, hotels, hotels, financial institutions, etc., it is often necessary to form a dedicated telephone network within the system, and also need the internal dedicated network to communicate with the external telephone system, which can be It is realized through a private automatic branch exchange (Private Automatic Branch Exchange, referred to as "PABX"). The so-called PABX refers to a special telephone exchange that automatically connects the internal subscriber line to the external line of the telephone system.

The emergence of the virtual exchange (CENTREX) has changed the traditional scheme of using PABX to form a private network. CENTREX is a centralized exchange service, which divides some users, such as an enterprise, into a basic user group on the communication node, and provides various functions of PABX, and also provides some unique telecommunication network service functions. Wherein, the communication node may be a program-controlled exchange of an end office, a toll office or a gateway office. CENTREX and PABX have a certain degree of similarity in a certain sense, they both provide a centralized user group with controllable internal telephone switching capabilities, complete group calls between internal and external, and add a series of supplementary services . Compared with PABX's independent hardware and software and certain occupied space, CENTREX is mainly a software concept, and all the software that makes up CENTREX is placed in the public exchange.

It can be understood from the above introduction that the CENTREX service is actually a service that uses the resources of the Public Switched Telephone Network ("PSTN" for short) to form a private network and provide virtual PABX functions for users of the public network. With CENTREX, the user end does not install PABX, and the digital program-controlled switchboard used by the office directly provides all telephones to the enterprise. Although there is no PABX, all the telephones of this user can enjoy the basic functions of PABX, just like this The PABX is concentrated in the office switch. The introduction of CENTREX replaces PABX, simplifies the network level, facilitates unified planning and management, and is of great significance to the improvement of the overall operation level of the network and the increase of market coverage and business income. And because CENTREX uses PSTN resources to form a dedicated network, it has the advantages of flexible networking, diverse services, and professional maintenance, so it has been widely used.

The existing technology can realize ordinary CENTREX services on the communication nodes, and the access is based on the traditional public switched telephone network (Public Switched Telephone Network, referred to as "PSTN") users, such as analog users, V5 users and integrated services digital network (Integrated Services Digital Network, referred to as "ISDN") users, etc. A schematic diagram of the composition of a relatively simple system using a common CENTREX group is shown in Figure 1. The three users in FIG. 1 are respectively connected to a communication node 10 through their respective interfaces to form a dedicated group.

Considering the geographical dispersion of users in the private network, when the users of a user group belong to different communication nodes 10, using No. 7 (No.7) signaling network can connect multiple geographically dispersed CENTREX groups into one , become a wide area CENTREX (Wide Area CENTREX, referred to as "WAC") group, and the use of services is no different from that of a single CENTREX group, because there is No.7 signaling support on the public network, so that the addition or modification of new services is equivalent Simple and easy. In WAC, the communication node 10 provides a WAC interface, so that users distributed in different exchanges can belong to the same CENTREX group, and realize basic services and user management in a common CENTREX group. A schematic diagram of the composition of a relatively simple system using WAC groups is shown in FIG. 2 . Wherein, the PSTN user interface refers to the interface between the communication node 10 and the user supported by the above-mentioned common CENTREX.

In order to support PSTN users to form a CENTREX group, the communication node 10 includes a call control function module and a protocol stack processing module. In addition, the communication node 10 needs a CENTREX service processing function module for PSTN users and a data management function module for PSTN users, wherein the protocol stack processing module Realize the encoding and decoding processing of signaling; the call control function module realizes various types of calls such as inter-user calls, intra-group user calls, out-group user calls, outgoing calls and incoming calls; CENTREX service processing function module for PSTN users It is used to realize various CENTREX new services and supplementary services; the PSTN user data management function module is used to realize CENTREX groups. To support the WAC, the communication node 10 also needs the WAC interface of the PSTN user to realize the inter-office WAC connection.

In recent years, with the development of the Internet, the number of Internet Protocol (Internet Protocol, referred to as "IP") group users has increased year by year, and IP CENTREX came into being. The so-called IPCENTREX refers to the provision of CENTREX business, but the core network of IPCENTREX is based on IP packet switching. However, the core network of the existing CENTREX is the PSTN circuit switching network, so how to access IP users in the PSTN network and realize the CENTREX service has become a very real problem.

In practical application, the above solution has the following problems: no matter it is ordinary CENTREX service or WAC service, it does not support the access of IP packet users, and it is impossible to access IP packet users and provide CENTREX and WAC on the basis of the existing PSTN network business.

The main reason for this situation is that the core network of the existing CENTREX and WAC services is based on the PSTN circuit switching network, and the communication nodes do not have interfaces for IP packet user access, protocol processing, and call access for IP packet user access. Management and CENTREX business management and other functions, so it does not support the access of IP packet users.

Contents of the invention

In view of this, the main purpose of the present invention is to provide a virtual switch system, so that the existing CENTREX service based on the PSTN network can access IP packet users, realize the separate grouping of IP packet users and the mixing of IP packet users and traditional PSTN users Group, while providing WAC interface and services for IP group users.

In order to achieve the above object, the present invention provides a virtual switch system, including a first subsystem, used to realize the virtual switch function based on the public switched telephone network, and also includes

The second subsystem is used to convert the IP-based media and protocols from IP packet users into public switched telephone network-based media and protocols, and send them to the first subsystem for processing, and also use for converting the PSTN-based media and protocols from the first subsystem into Internet Protocol-based media and protocols, and sending them to the packet users.

Wherein, the first subsystem and the second subsystem are located in a communication node, and the communication node receives and processes signaling from an Internet protocol packet user through a first interface, and sends signaling to the packet user to implement Control over the group users.

The signaling received and sent by the first interface may be one of media gateway control protocol, H.248 protocol, session initiation protocol, H.323 protocol or any combination thereof.

The second subsystem includes a packet user interface module, a packet protocol stack processing module, a packet user call control module, a packet user virtual switch service processing module, and a packet user data management module, wherein

The group user interface module is configured to realize the function of the first interface;

The packet protocol stack processing module is used to decode the packet user signaling from the packet user interface module and generate call signaling to send to the packet user call control module, and to process the packet user signaling from the packet user call control module Encoding the call signaling and generating packet user signaling to send to the packet user interface module;

The packet user call control module is used to realize various types of calls of the packet user, process the call signaling from the packet protocol stack processing module, generate service processing signaling and send it to the packet user virtual switch The service processing module processes the service processing signaling from the packet user virtual switch service processing module, generates call signaling and sends it to the packet protocol stack processing module;

The packet user virtual switch service processing module is used to realize the new service and supplementary service of the virtual switch of the packet user, and interact with the packet user call control module through service processing signaling;

The packet subscriber data management module is used to manage the packet subscriber information, including virtual switch group information, which is inquired by the packet subscriber virtual switch service processing module and the packet subscriber call control module during call and service processing.

The call types implemented by the group user call control module include: calls between the group users, calls between the group users and public switched telephone network users, calls within the group user groups, calls in the group user groups Outgoing calls, outgoing calls of the group users, and incoming calls of the group users.

The group form of the virtual switch group of the group users implemented by the group user data management module may be a separate group of the group users, or a mixed group of the group users and public switched telephone network users.

The second subsystem also provides a wide area virtual switch interface for the packet subscriber.

The first subsystem can also support the access of users of the public switched telephone network through an analog interface, an integrated service digital network interface and a V5 interface.

Through comparison, it can be found that the difference between the technical solution of the present invention and the prior art is that the CENTREX system of the present invention completes protocol conversion and media conversion by modifying the communication node to increase the packet user interface or adding a gateway, and realizes IP packet in PSTN-based CENTREX user access.

The difference in this technical solution has brought more obvious beneficial effects, that is, firstly, the PSTN-based CENTREX system that can access IP packet users in the present invention realizes the CENTREX service of IP packet users, and connects a large number of IP packet users. Communication nodes, making full use of IP network resources, reducing networking and operating costs; secondly, this solution has no impact on the users of the original PSTN CENTREX service, and has the least impact on network transformation and impact; third, this solution can pass traffic The station completes the management and maintenance of the CENTREX group of IP group users, so the IP group users and equipment can be planned and managed in a unified manner, the maintenance and management level is high, and the equipment operation is more stable and reliable.

Description of drawings

Figure 1 is a schematic diagram of a relatively simple system using a common CENTREX group;

Figure 2 is a schematic diagram of a relatively simple system composition using a WAC group;

Fig. 3 is the CENTREX system composition diagram based on PSTN that realizes by modifying the communication node that can access IP grouping user according to a preferred embodiment of the present invention;

Fig. 4 is a schematic diagram of the composition of the PSTN-based CENTREX system that can access IP packet users by adding gateways according to a preferred embodiment of the present invention;

Fig. 5 is a structural diagram of modules related to IP packet user processing in a communication node according to a preferred embodiment of the present invention.

Detailed ways

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings.

The advantage of the present invention is that it realizes the unified management of IP group users and common users, integrates IP users and common users in call processing and CENTREX service processing, and makes IP group users It has the same business attributes and business models as ordinary users, reducing the links of data configuration and management.

The invention includes the access of IP users and the encoding and decoding of IP protocol in the communication node, and realizes the processing of IP users as a whole. In realizing the conversion between the IP media stream and the PSTN media stream, the present invention preferably realizes one-time conversion, directly converts the IP media stream into the PSTN media stream and directly converts the PSTN media stream into the IP media stream, There is no need for multiple conversions, thereby avoiding the resulting decline in call quality. The built-in media conversion part of the present invention can directly convert the RTP media flow based on UDP/IP into an analog voice signal or a PCM digital signal, and the specific interface can be a common subscriber line, V5, ISDN, analog trunk line, E1, T1, STM, etc.

In order to enable the existing PSTN-based CENTREX service to access IP packet users, it is first necessary to enable IP packet users to access communication nodes. Therefore, protocol conversion and media conversion can be completed by adding corresponding modules in communication nodes, thereby providing Appropriate interfaces to support the access of IP packet users and the provision of CENTREX services, and the data of IP packet users can also be converted through the functions of gateway protocol conversion and media conversion to realize the access of IP packet users and the provision of CENTREX services .

The solution of the present invention will be described below in combination with specific embodiments of the present invention.

By modifying the communication nodes to complete functions such as protocol conversion and media conversion, it is possible to access IP packet users in CENTREX based on PSTN.

According to a preferred embodiment of the present invention, a schematic composition diagram of a PSTN-based CENTREX system that can access IP packet users by modifying communication nodes is shown in FIG. 3 .

The CENTREX system accessible to IP packet users realized by modifying communication nodes includes: at least one IP packet user 20 , several PSTN users 30 and communication nodes 10 .

The PSTN user 30 and the communication node 10 are connected through the PSTN user interface, and the IP packet user 20 and the communication node 10 are connected through the interface 1 .

As shown in Figure 5, in addition to the functional modules of the traditional communication node 10, in order to support the access of IP users and provide them with CENTREX services, the communication node 10 needs to complete functions such as protocol conversion and media conversion. The communication node 10 also includes: IP Packet user interface module, IP packet protocol stack processing module, IP packet user call control module, IP packet user CENTREX service processing module and IP packet user data management module. In a preferred embodiment of the present invention, the communication node 10 also provides an IP packet user WAC interface to realize inter-office WAC connection.

The IP packet user interface module is used to provide interface 1 and IP packet user 20 connection. The communication node 10 receives the signaling sent by the IP packet user 20 through the interface 1, and sends the signaling through the interface 1 to control the IP packet user 20. Wherein, the signaling supported by interface 1 may be Media Gateway Control Protocol (Medium Gateway Control Protocol, "MGCP"), H.248, Session Initiation Protocol (Session Initation Protocol, "SIP") or H.323. Those skilled in the art can understand that the signaling supported by interface 1 can also be other protocols, which can be changed by administrators according to needs without affecting the essence of the present invention.

The IP packet protocol stack processing module is used to realize the encoding and decoding processing of packet user signaling. Wherein, the IP packet protocol stack processing module is similar to the protocol stack processing module of the traditional communication node 10. The difference is that the traditional protocol stack processing module processes the relevant protocols of the PSTN network, and the IP packet protocol stack processing module processes the protocol of the IP packet .

The IP packet user call control module is used to realize various types of calls of the IP packet user 20 . Among them, the call types include: calls between IP group users 20, calls between IP group users 20 and PSTN users 30, calls within the group of IP group users 20, calls outside the group of IP group users 20, outbound calls of IP group users 20 and various call types such as incoming calls of IP packet users 20.

The IP packet user CENTREX service processing module is used to realize various CENTREX new services and supplementary services of the IP packet user 20 . Wherein, the CENTREX service provided to the IP packet user 20 may be the same as the CENTREX service provided to the PSTN user 30 .

The IP packet user data management module is used to manage the information of the group users, which includes virtual switch group information, and the CENTREX group of the IP group users 20 can be realized through these information. Wherein, the CENTREX group of the IP packet user 20 may be a separate group of the IP packet user 20, or may be a mixed group of the IP packet user and the PSTN user.

Each module related to the group user in the communication node 10 has been introduced above, and the connection relationship between each module is explained here. The IP packet user interface module and the IP packet protocol stack processing module interact through packet user signaling; the IP packet protocol stack processing module and the IP packet user call control module interact through call signaling; the IP packet user call control module and the IP The packet user CENTREX service processing modules interact through service processing signaling; the IP packet user call control module and the IP packet user CENTREX service processing module need to query the packet user information from the IP packet user data management module during the call and service processing (where Contains virtual switch group information).

The following example illustrates the process of these modules serving IP packet users:

When the IP packet user 20 sends packet user signaling to the communication node 10, the IP packet user interface module sends the packet user signaling to the IP packet protocol stack processing module; the IP packet protocol stack processing module receives the packet user signaling Decode it, generate corresponding call signaling, and send it to the IP group user call control module; the IP group user call control module processes the received call signaling and finds that the call is a group call, which needs to be managed from the IP group user data management The module queries the virtual switch group information of the IP packet user, completes call processing according to the queried information, and sends a service processing instruction to the IP packet user CENTREX service processing module according to the corresponding service of the call; the IP packet user CENTREX service processing module responds The service processing instruction completes the service processing function, and the processing result is fed back to the IP packet user 20 through the IP packet user call control module, the IP packet protocol stack processing module and the IP packet user interface module.

It should be noted that the PSTN-based CENTREX system shown in FIG. 3 that can access IP packet users by modifying communication nodes may not include PSTN users 30, and at this time, IP packet users 20 are grouped separately.

By adding the access gateway to complete functions such as protocol conversion and media conversion, the access of IP packet users can also be realized in CENTREX based on PSTN.

According to a preferred embodiment of the present invention, a schematic composition diagram of a PSTN-based CENTREX system that can access IP packet users by adding a gateway is shown in FIG. 4 .

The PSTN-based CENTREX system that can be accessed by adding gateways to IP packet users includes: a communication node 10, at least one IP packet user 20, several PSTN users 30, an access gateway 50 and an IP gateway 60.

The communication node 10 is connected with the access gateway 50, and the IP gateway 60 is connected with the IP packet user 20 in sequence; the communication node 10 and the PSTN user 30 are connected through the PSTN user interface.

Wherein, the communication node 10 is the same as the communication node in the existing PSTN-based CENTREX.

The access gateway 50 is used to realize the interface function between the PSTN network and the access network, and supports protocols such as V5 or ISDN on the access side of the PSTN network. The IP gateway 60 is used to connect packet users to the IP network, and implement codec conversion of media streams between the access network and the IP network. Support MGCP, H.248, SIP or H.323 protocols on the IP side. The interface between the access gateway and the IP gateway can be a standard E1 or T1 interface, or a private interface protocol between the two.

Those skilled in the art can understand that through the protocol and media conversion of the gateway, the communication node 10 can access the IP packet user 20 and provide the same CENTREX service as the PSTN user.

Although the present invention has been illustrated and described with reference to certain preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein, and without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (8)

1. A virtual exchange system, comprising a first subsystem, for realizing the virtual exchange function based on the public switched telephone network, characterized in that it also includes The second subsystem is used to convert the IP-based media and protocols from IP packet users into public switched telephone network-based media and protocols, and send them to the first subsystem for processing, and also use for converting the PSTN-based media and protocols from the first subsystem into Internet Protocol-based media and protocols, and sending them to the packet users. 2. The virtual switch system according to claim 1, wherein the first subsystem and the second subsystem are located in a communication node, and the communication node receives and processes data from the Internet protocol packet user via the first interface. signaling, and send signaling to the group user to implement control over the group user. 3. The virtual exchange system according to claim 2, wherein the signaling received and sent by the first interface can be one of the media gateway control protocol, H.248 protocol, session initiation protocol, and H.323 protocol. one or any combination thereof. 4. virtual exchange system according to claim 2, is characterized in that, comprises packet subscriber interface module, packet protocol stack processing module, packet subscriber call control module, packet subscriber virtual switch service processing module and in the second subsystem Group user data management module, wherein The group user interface module is configured to realize the function of the first interface; The packet protocol stack processing module is used to decode the packet user signaling from the packet user interface module and generate call signaling to send to the packet user call control module, and to process the packet user signaling from the packet user call control module Encoding the call signaling and generating packet user signaling to send to the packet user interface module; The packet user call control module is used to realize various types of calls of the packet user, process the call signaling from the packet protocol stack processing module, generate service processing signaling and send it to the packet user virtual switch The service processing module processes the service processing signaling from the packet user virtual switch service processing module, generates call signaling and sends it to the packet protocol stack processing module; The packet user virtual switch service processing module is used to realize the new service and supplementary service of the virtual switch of the packet user, and interact with the packet user call control module through service processing signaling; The packet subscriber data management module is used to manage the packet subscriber information, including virtual switch group information, which is inquired by the packet subscriber virtual switch service processing module and the packet subscriber call control module during call and service processing. 5. The virtual exchange system according to claim 4, wherein the call type implemented by the group user call control module includes: calls between the group users, calls between the group users and public switched telephone network users calls between the group users, calls within the group user group, calls outside the group user group, outgoing calls of the group user and incoming calls of the group user. 6. The virtual switch system according to claim 4, characterized in that, the virtual switch group form of the packet user realized by the packet user data management module can be a separate group of the packet user, or can be all The mixed group of group users and public switched telephone network users mentioned above. 7. The virtual switch system according to claim 1, wherein the second subsystem further provides a wide-area virtual switch interface for the group user. 8. The virtual switch system according to claim 1, wherein the first subsystem can also support the access of users of the public switched telephone network through an analog interface, an ISDN interface and a V5 interface.

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